Calipso is a simple NodeJS content management system, built along similar themes to Drupal and Wordpress, that is designed to be fast, flexible and simple.
For additional details, including installation instructions, please visit the home page: http://calip.so/
If you would like to contribute, please take a look at the issues list as this will have the most up to date view of work that needs to be done for the next minor release. Otherwise, please just pm myself (cliftonc) or dennis (dennishall) and we can suggest some places for you to start.
If you want to try it out as quickly as possible, please install MongoDB, and then use NPM:
npm install calipso -g
cd /var/www
calipso create-site MySite
cd MySite
calipso
This is relatively new, and as I am working on the module management functions there are some tricky dependencies in core (e.g. expat, mongodb) that require compilation and can cause issues. Please raise / update issues if you find them.